Safety alarm

ABSTRACT

A safety alarm for machines having an &#39;&#39;&#39;&#39;automatic&#39;&#39;&#39;&#39; mode of operation comprising a pair of timers actuated by manually operable switches, the said timers connected in series to prevent the machine from converting to the &#39;&#39;&#39;&#39;automatic&#39;&#39;&#39;&#39; mode of operation until both have timed-out and requiring the uninterrupted manual actuation of said switches during the period of timeout, and audible alarm means energized continuously while the machine is set for &#39;&#39;&#39;&#39;automatic&#39;&#39;&#39;&#39; mode of operation, the said alarm means being deenergized when both timers have timed out.

United States Patent [7 2] Inventors Raymond J. Sulat West Caldwell;Moses W. Hunt, Newark, both of NJ. [21] Appl. No. 841,048 [22] FiledJuly 11, 1969 [45] Patented Dec. 28, 1971 [73] Assignee Hudson Tool &Die Co., Inc.

Newark, NJ.

[54] SAFETY ALARM 7 Claims, 1 Drawing Fig.

[52] US. Cl 340/279, 307/142, 317/135, 340/3094, 340/3096 [51] Int. Cl..H01h 47/22 [50] Field oISearch 317/135;

TO AUTOMATIC [56] References Cited UNITED STATES PATENTS 2,250,8287/1941 Foss 340/276 3,089,985 5/1963 Camfield et al.. 317/135 3,359,53912/1967 Fink 318/446 Primary Examiner-John W. Caldwell, Jr. AssistantExaminer-J, Michael Bobbitt Attorney-Popper, Bain, Bobis & GilfillanABSTRACT: A safety alarm for machines having an automatic mode ofoperation comprising a pair of timers actuated by manually operableswitches, the said timers connected in series to prevent the machinefrom converting to the "automatic" mode of operation until both havetimed-out and requiring the uninterrupted manual actuation of saidswitches during the period of timeout, and audible alarm means energizedcontinuously while the machine is set for automatic mode of operation,the said alarm means being deenergized when both timers have timed out.

MODE CONTROL TO POWER 0 SOURCE E55 1 1 rma-R: 1 AUDIBLE J ALAR 1 I TOPOWER T I 65? SOURCE I LAMP r\ 41 l l l 22 FROM AUTOMATIC MODE CONTROL fLAMP GROUND Patented Dec. 28, 1971 TO AUTOMATIC MODE CONTROL TO POWER 0SOURCE f AUDIBLE LAMP TO POWER SOURCE FROM AUTOMATIC MODE CONTROL GROUNDO INVENTORS RAYMOND J SULAT MOSES W HUNT A T TORNEYS SAFETY ALARMBACKGROUND OF INVENTION Many machines such as hydraulic presses areprovided with electrical controls which permit the press to operateeither in manual mode of operation or an automatic mode of operation.During setup or maintenance, the press is set for manual operation.However, if the operator fails to reset the controls from automatic tomanual there is great danger of severe inj ury as the press unexpectedlycontinues to run after actuation. Thus there is a great need forfail-safe means to prevent unintentional operation of the press in theautomatic mode.

The purpose of the safety alarm disclosed herein in is to prevent thepress from being energized for automatic operation without theconscious, manual actuation of a pair of spaced-apart switchescontinuously and uninterruptedly for a substantial period of time duringwhich period an audible alarm sounds. This guarantees that the operatorwill, at all times, be conscious of the fact that the press is set forautomatic operation.

SUMMARY OF INVENTION A safety alarm for converting apparatus from amanual mode of operation to an automatic mode of operation comprising atleast one timing means connected in series with means for energizing anautomatic mode of operation of the apparatus, manually operable meansfor energizing the timing means, the timing means timing-out only if thesaid manually operable means are actuated continuously anduninterruptedly for a significant period of time, the timing meansconnecting the apparatus to automatic mode of operation only when timedout, and alarm means connected to the timing means, operable when theapparatus is set for automatic mode of operation and the timing means isuntimed out.

PREFERRED EMBODIMENT OF INVENTION These objects and advantages as wellas other objects and advantages may be achieved by the safety alarmdescribed and claimed herein a preferred embodiment of which isillustrated in the drawings in which;

FIG. 1 is a schematic wiring diagram of the safety alarm.

Referring now to the drawings in detail, the safety alarm comprises apair of manually operable switches 11 and 12 connected in series witheach other and the safety alarm itself. The switches 11 and 12 arenormally physically located on the apparatus and are spaced apart adistance sufficient to require simultaneous actuation by both hands.

The switches 11 and 12 are connected in series with a pair of timers 13and 14. Each of the timers 13 and 14 has a double-pole double-throwmicroswitch associated with it. Normally open contacts 15 and 16 areassociated with timer 13 as is normally closed contact 17. Normally opencontact 18 and normally closed contact 19 are associated with timer 14.

It will be observed that when normally open contacts 15 and 16 of timer13 and normally open contact 18 of timer 14 are opened, the circuit tothe automatic mode of operation is interrupted. Both timers l3 and 14must time out in order to close the normally open contacts 15 and 16 andthe normally closed contact 17. Normally open contact 16 of timer l3 andnormally closed contact 17 of timer 14 are in series insuring isolationof the automatic" mode circuit until both timers 13 and 14 time out. Theautomatic mode control circuit of the apparatus to which the safetyalarm is connected provides power to timers 13 and 14 retaining normallyopened contacts 16 and 18 in a closed configuration until the automaticmode control circuit is broken by means on the apparatus controlled bythe alarm.

An audible alarm is connected in with the automatic" mode circuit of theapparatus such that the alarm 20 is enerv gized whenever the apparatusis set for automatic operation but is inoperative. The power source tothe alarm 20 passes through normally closed contacts 17 and 19 of timersl3 and 14 respectively, Hence, when the timers l3 and 14 time out,

the alarm 20 is deenergized. If either of the timers 13 or 14 fails totime out, the alarm 20 will remain energized and the automatic mode ofoperation deenergized.

While the safety alarm has been illustrated with two timers 13 and 14any number of timers can be made to function in the same way.Nevertheless, although a single timer will function in the same way, itwill not provide as great reliability as two or more timers. If thesingle timer should malfunction, the circuit to the automatic mode ofoperation could be energized unintentionally. In addition, the alarm 20might well be deenergized by the same malfunction. However, thelikelihood of two timers malfunctioning at the same time and in the samemanner as to deenergize the alarm is extremely remote thereby providingsubstantially greater protection.

A pair of pilot lights 21 and 22 are connected to the timers l3 and 14respectively. The pilot lights 21 and 22 illuminate when the respectivetimers 13 and 14 have timed out.

The pilot lights 21 and 22 will also illuminate if one of the normallyopen contacts of the switch associated with it shorts out. Thus, in theevent of a failure of one of the timers, its pilot light would remaindeenergized and would indicate the deactivated portion of the circuit.On the other hand, if one of the pilot lights is illuminated when itshould not be illuminated, it would indicate that one of the normallyopen contacts associated with it has been frozen closed or shorted out.Thus, the pilot lights 21 and 22 provide visible indication ofmalfunction both of the timers l3 and 14 and the respective contacts l5,16, 17 and 18.

While the safety alarm has been described and illustrated as anelectrically operated device, all of the'components could be equally aswell actuated pneumatically or hydraulically. Pneumatic or hydraulicanalogs of the electrical safety alarm illustrated in the drawings arecontemplated as being within the scope of the claims.

The foregoing description is merely intended to illustrate andembodiment of the invention. The component parts have been shown anddescribed. They each may have substitutes which may perform asubstantially similar function; such substitutes may be known as propersubstitutes for the said components and may have actually been known orinvented before the present invention.

We claim:

1. A safety alarm for apparatus having selectable manual and automaticmodes of operation comprising a. at least one timing means operativelyconnected with means for energizing automatic mode of operation ofapparatus,

b. manually operable means for energizing the timing means, the timingmeans timing out only if the said manually operable means are actuateduninterruptedly for a significant period of time,

c. the timing means converting the apparatus to automatic mode ofoperation only when all said timing means have timed out.

2. A safety alarm for apparatus having selectable manual and automaticmodes of operation comprising a. the structure in accordance with claim1 and b. alarm means operatively connected to both the timing means andmeans for energizing automatic mode of operation of the apparatus,

c. the alann means being energized when the apparatus is programmed forautomatic mode of operation and deenergized only when the timing meanstime out.

3. A safety alarm for apparatus having selectable manual and automaticmodes of operation comprising a. the structure in accordance with claim1 in which b. there are at least a pair of manually operable meansspaced apart sufi'rciently that each said means must be actuated by aseparate hand.

4. A safety alarm for apparatus having selectable manual and automaticmodes of operation comprising a. the structure in accordance with claim1 in which b. the timing means is an electrically actuated timerconoperable means are actuated uninterruptedly for a signifiverted inseries with the means for energizing automatic cant period of time,

mode of operation. d. the timing means converting the apparatus toautomatic A Saki) alarm pp 'f havms Selectable manual mode of operationonly when all said timing means have and automatlc modes ofoperatloncompnsmg 5 i d out an f accPrdance claim whlqh 7. A safety alarm forapparatus having selectable manual b. the timing means is anelectrically actuated timer conand automatic modes ofopemtion comprisingnected in series with the means for energizing automatic 3' theStructure in accordance with daim 6 and mode of operation. 6. A safetyalarm for apparatus having selectable manual 10 and automatic modes ofoperation comprising a. the structure in accordance with claim 1 inwhich b. there are at least two timing means operatively connected withthe means for energizing automatic mode of operation of the apparatus,

c. each of the timing means timing out only if the manually b. alarmmeans connected to both the timing means and the means for energizingautomatic mode of operation of the apparatus c. the alarm means beingenergized when the apparatus is programmed for automatic mode ofoperation and deenergized only when the timing means time out.

1. A safety alarm for apparatus having selectable manual and automaticmodes of operation comprising a. at least one timing means operativelyconnected with means for energizing automatic mode of operation ofapparatus, b. manually operable means for energizing the timing means,the timing means timing out only if the said manually operable means areactuated uninterruptedly for a significant period of time, c. the timingmeans converting the apparatus to automatic mode of operation only whenaLl said timing means have timed out.
 2. A safety alarm for apparatushaving selectable manual and automatic modes of operation comprising a.the structure in accordance with claim 1 and b. alarm means operativelyconnected to both the timing means and means for energizing automaticmode of operation of the apparatus, c. the alarm means being energizedwhen the apparatus is programmed for automatic mode of operation anddeenergized only when the timing means time out.
 3. A safety alarm forapparatus having selectable manual and automatic modes of operationcomprising a. the structure in accordance with claim 1 in which b. thereare at least a pair of manually operable means spaced apart sufficientlythat each said means must be actuated by a separate hand.
 4. A safetyalarm for apparatus having selectable manual and automatic modes ofoperation comprising a. the structure in accordance with claim 1 inwhich b. the timing means is an electrically actuated timer converted inseries with the means for energizing automatic mode of operation.
 5. Asafety alarm for apparatus having selectable manual and automatic modesof operation comprising a. the structure in accordance with claim 2 inwhich b. the timing means is an electrically actuated timer connected inseries with the means for energizing automatic mode of operation.
 6. Asafety alarm for apparatus having selectable manual and automatic modesof operation comprising a. the structure in accordance with claim 1 inwhich b. there are at least two timing means operatively connected withthe means for energizing automatic mode of operation of the apparatus,c. each of the timing means timing out only if the manually operablemeans are actuated uninterruptedly for a significant period of time, d.the timing means converting the apparatus to automatic mode of operationonly when all said timing means have timed out.
 7. A safety alarm forapparatus having selectable manual and automatic modes of operationcomprising a. the structure in accordance with claim 6 and b. alarmmeans connected to both the timing means and the means for energizingautomatic mode of operation of the apparatus c. the alarm means beingenergized when the apparatus is programmed for automatic mode ofoperation and deenergized only when the timing means time out.